Summary
Twenty-seven adult male New Zealand rabbits (3–4 kgs) were used in this study. Six
rabbits received vehicle, 3 groups of 6 each received doses of 4,5-bis(p-methoxyphenyl)-2-(trifluoromethyl)-
thiazole, (U-53,059), at 0.3 mg/kg, 3.0 mg/kg and 30.0 mg/kg/day respectively. Drug
and vehicle doses were given orally each day starting 3 days before balloon injury
and continuing for the entire 2 week time period. Three rabbits were used as nontreated
sham controls. In the vehicle and U-53,059 treated groups aortae were denuded of endothelial
cells by balloon catheter injury. Two weeks after injury platelet aggregation to collagen
was measured and the aortae removed for analysis of surface characteristics by scanning
electron microscopy and lesion size by morphometry. All doses of U-53,059 inhibited
platelet aggregation. The 3.0 and 30.0 mg/kg groups had the greatest inhibitory effect.
All balloon injured aortae had the same morphologic characteristics. All vessels had
similar extent and intensity of Evan’s blue staining, similar areas of leukocyte/platelet
adhesion, and a myointimal cell cover of transformed smooth muscle cells. The myointimal
proliferative response was not inhibited at any of the drug doses studied.
Key Words
Anti-atherogenic - Proliferation - Platelet - Adhesion - Inhibition and leukocyte
